Drainage system with O-ring

ABSTRACT

A drainage system, the drainage system comprising a container having an interior and a mouth, the mouth comprising an outer surface and an opening, a frangible seal covering the opening, a cap secured to the mouth and in fluid communication with a drainage line, the cap having an inner surface configured to engage with the outer surface of the mouth, an O-ring located at least partially between the outer surface of the mouth and the inner surface of the cap and configured to form a fluid seal between a space defined by the cap and the space located externally of the drainage system, and a retaining ring circumferentially engaging the cap.

CROSS-REFERENCE

This application is a continuation of U.S. patent application Ser. No.14/788,198, filed Jun. 30, 2015 entitled “Drainage System with O-Ring,”the details of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to the field of medical devices and, inparticular, to a device useful for withdrawing and containing fluidsfrom a patient body.

BACKGROUND

Body fluids may need to be withdrawn from a patient in the course ofmedical treatment. Two common medical procedures requiring fluid removalare thoracentesis and paracentesis.

In paracentesis, peritoneal fluid is aspirated from the abdomen. Typicalpatients have tense ascites resulting from liver disease and portalhypertension, which may cause discomfort, respiratory distress, and theformation and rupture of umbilical hernias. Paracentesis has beenobserved to provide quick and effective relief with few adverse sideeffects. Other treatment options, such as the use of diuretics, areavailable, but may not provide as effective relief as paracentesis.Additionally, many patients with ascites have renal impairment andcannot use the high doses of diuretics necessary to effectively treatthe ascites. See “Large-Volume Paracentesis in Nonedematous Patientswith Tense-Ascites: Its Effect on Intravascular Volume,” Pinto et al.,Hepatology, Vol. 8, No. 2, pp. 207-210, 1988. Relatively large volumesof fluid, such as five liters, may be withdrawn from a patient duringone paracentesis procedure.

Many existing devices are capable of performing paracentesis. At itssimplest, a paracentesis device need only include a hollow needle withone end inserted into the patient and the other end attached to anegative pressure device, such as a syringe or vacuum bottle. However,more specialized devices have been developed to allow safer, morecomfortable, and more sanitary paracentesis. These devices may allow forbody fluid to be dispensed into at least two containers, so that onecontainer may be filled with fluid for diagnostic purposes and the othercontainer may be filled with waste fluid. Another development has beenthe use of Kuss or Verres type needle assemblies, where a blunt drainageneedle is attached to a retractile sharp introducer needle. This reducesthe likelihood of the sharp needle damaging internal tissue duringparacentesis. A further development is to drain body fluid through ablunt-tipped catheter introduced by a sharp introducing needle, whichallows the sharp needle to be removed from the patient after arelatively quick introduction process and avoids the prolonged presenceof a sharp needle in the body of the patient.

Problems may arise when drainage is diverted from one container toanother if the drainage system is not airtight. Air could contaminate asample or enter the body of the patient and cause injury. Known devicesthat are meant to be airtight have tubes and multiple containersattached to the devices which make the devices cumbersome and somewhatdifficult to insert into the patient. Also, known devices requiremanipulation of a manual valve, such as a stopcock to work effectively.If the stopcock is not set at the proper setting, the device may admitair into the patient or otherwise malfunction. Problems also may arisein devices which allow a needle assembly to be withdrawn. Air must beprevented from entering the patient when the fluid is withdrawn. Also,body fluid must be prevented from leaking out of the device through thespace formerly occupied by the needle assembly.

Thoracentesis is a procedure similar to paracentesis, except thateffusion fluid is withdrawn from the pleural region instead of theabdomen. Normally, the pleural space contains approximately 5 to 20 mlof fluid. The fluid is the result of the hydrostatic-onctotic pressureof the capillaries of the parietal pleura. The turnover of the fluid inthe pleural space is normally quite rapid, so that 5 to 10 liters offluid move through the pleural space each day. A disruption in thebalance between the movement of fluid into the pleural space and themovement of fluid out of the pleural space may produce excessive fluidaccumulation in the pleural space. Pleural effusion is particularlycommon in patients with disseminated breast cancer, lung cancer orlymphatic cancer and patients with congestive heart failure, but alsooccurs in patients with many other forms of malignancy.

Pleural effusion may cause dyspnea, coughing, and chest pain, whichdiminish a patient's quality of life. Although pleural effusiontypically occurs toward the end of terminal malignancies, such as breastcancer, it occurs earlier in other diseases. Therefore, relieving theclinical manifestations of pleural effusion is for real and extendedadvantage to the patient. For example, non-breast cancer patients withpleural effusion have been known to survive for years. See “PleuralEffusion in Cancer Patients,” Izbicki et al., Cancer, October 1975, p.1511.

There are several treatments for pleural effusion. If the patient isasymptomatic and the effusion is known to be malignant or paramalignant,no treatment may be required. Pleurectomy and pleural abrasion aregenerally effective in obliterating the pleural space, thus controllingthe malignant pleural effusion. However, pleurectomy is a major surgicalprocedure associated with substantial morbidity and some mortality.Chemotherapy is generally disappointing; however, it may produce goodresponses for patients with lymphoma, breast cancer, or small-cellcarcinoma. Another approach is to surgically implant a chest tube.However, such a tube is painful to the patient, both when it is insertedand during the time that it remains in the pleural space. Improvementson the traditional chest tube are described in U.S. Pat. No. 5,484,401.

Despite other treatment options, thoracentesis remains the most commonapproach to removing pleural fluid. However, thoracentesis poses thedanger of causing pneumothorax, a collapsed lung. Pneumothorax can becaused directly by puncturing a lung with a needle assembly or cathetertip or indirectly by allowing air to enter the pleural space. Normally,the pleural space is at negative pressure relative to the atmosphere,which helps keep the lungs expanded. If the atmosphere is allowed tocommunicate with the pleural space, the pleural space may no longer beat negative pressure and pneumothorax may result.

Thoracentesis devices have been developed to reduce the risk ofpneumothorax and other similar problems that may result from theprocedure. In general, these devices incorporate similar protections asdo paracentesis devices. For example, U.S. Pat. No. 4,447,235 by Clarkediscloses a thoracentesis device with a catheter introduced by aremovable needle assembly, with a valve that closes upon removal of theneedle assembly. The purpose of the valve is to prevent air fromentering the body of the patient. U.S. Pat. Nos. 4,784,156, 4,832,044,4,840,184, and 4,844,087 by Garg disclose similar devices with a manualvalve that may be closed after withdrawal of the needle assembly.However, none of the previous devices allow for a truly fail-safeoperation, as various valves must be properly set by the operator whenchanging from one drain port to another or when withdrawing theintroducing needle assembly from the patient. Also, care must be takento avoid accidental withdrawal of the introducing needle assembly, as inthe disclosed devices where the needle assembly is not firmly attachedto the remainder of the device. Further, the disclosed valves that allowfor catheter drainage after removal of an introducing needle assemblyrely on a single contact point. Due to the possibly dire consequences ofa valve failure, such valves may not produce acceptably safethoracentesis.

A Verres-type needle assembly that may be used for thoracentesis isdisclosed in U.S. Pat. No. 5,334,159 by Turkel. While this reduces therisk of pneumothorax due to lung puncture, the Turkel device does notimprove the safety of thoracentesis when the introducing needle assemblyis withdrawn or solve the problems associated with multiple drainageports. Thus there is a need for a safer and more reliable device thatmay be used for paracentesis and thoracentesis. Another device isdescribed in U.S. Pat. No. 5,725,506 by Freeman, et al., which isincorporated by reference herein in its entirety.

Other difficulties with existing systems relate to manufacturing,storing and using the vacuum element. Syringes are sometimes used togenerate the vacuum, but syringes are somewhat complicated tomanufacture and use. An alternative vacuum source is a vacuum bottle. Inthat approach, a vacuum is created in an air-tight bottle at themanufacturing stage, and then the bottle is sealed. The bottle is thentapped at the time of use so that the vacuum can be applied to adrainage line to remove the undesired body fluids.

This is quite elegant in concept but somewhat difficult to implementperfectly in every individual unit. There is always some risk that thevacuum will be lost in transit before use, either by leaks, fractures orjust air permeating through a plastic wall. Moreover, the loss of vacuumis not necessarily apparent to the user; a bottle with a perfect vacuuminside looks no different than a bottle of air, but the drainageefficacy of the unit may be diminished upon loss of vacuum before use orduring use where the vacuum is wasted on pulling in air rather thanexerting drainage effectively from the patient. Another problem is intapping the bottle. This requires a system that pierces a vacuum sealbut does not allow air to enter the bottle, except through the drawline. One such system is described in commonly owned U.S. Pat. No.7,048,724 by Grossman et al, which is incorporated by reference hereinin its entirety.

In known systems utilizing a vacuum bottle, a cap may be provided thatacts as an interface between the bottle and a drainage line. Inpractice, it is typical for the junction of the cap and the bottle to beassembled with the use of an adhesive, such as a silicone adhesive gel.The silicone gel may act both to secure the cap to the bottle and tocreate a fluid seal at the junction.

Systems using a silicone adhesive have achieved positive results.However, silicone gel adhesive typically is expensive and manufacturingexpenses associated with applying a silicone gel remain high. Further,it can be difficult to apply a precise amount of adhesive during theassembly process to achieve consistent securing and sealing that willpatently maintain desired vacuum throughout the device live and usage.Silicone adhesives also typically can only dry and set one time, shortlyafter application, and therefore the system is generally shipped fullyassembled, and it may be difficult to interchange the vacuum bottles atthe medical facility.

In light of this background, it would be advantageous to provide animproved system utilizing a container, such as a vacuum bottle,connected to a drainage line that achieves sufficient securing andsealing between the container and cap without the need for the use of anadhesive.

BRIEF SUMMARY

A drainage system is provided. The drainage system comprises a containerhaving an interior and a mouth with an outer surface and an opening, afrangible seal covering the opening, a cap secured to the mouth and influid communication with a drainage line, the cap having an innersurface configured to engage with the outer surface of the mouth, and anO-ring located at least partially between the outer surface of the mouthand the inner surface of the cap. The term “frangible” is here definedto include being able to be punctured, pierced, or otherwiseinterrupted. The O-ring may be configured to form a fluid seal betweenan area within the cap and the conditions external to the drainagesystem. The drainage system may further comprise a retaining ringcircumferentially engaging the elastomeric cap.

In one embodiment, a spiked tube is positioned at least partially withinthe cap and is configured to pierce the frangible seal. An area withinthe cap and the interior of the container may be in fluid communicationwhen the frangible seal is pierced. The cap may comprise a taperedwidened body portion, and it may be formed from an opaque material.

In another embodiment, the mouth comprises a groove within the outersurface configured to seat the O-ring. Alternatively or in addition, thecap may comprise such a groove. The interior of the container may hold avacuum. Further, a stop may be provided on the cap and a container maycomprise a shoulder, wherein the stop is configured to contact theshoulder when the cap slides a first distance in the proximal directioninto engagement with the mouth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front cut-out schematic of one embodiment of a knowndrainage system.

FIG. 2 shows a front cut-out partial sectional view of a known drainagesystem having a collapsible bulb.

FIG. 3 shows a front cut-out partial view of a drainage system using asilicone adhesive at the junction of a cap and a container.

FIG. 4 shows a front cut-out partial view of a drainage system with anO-ring at the junction of a cap and a container

FIG. 5 shows a perspective view of an exemplary embodiment of aretaining ring.

FIG. 6 shows a perspective view of a drainage system comprising aretaining ring circumferentially engaging an elastomeric cap.

FIG. 7 shows a perspective cutout view of a drainage system comprising adrainage ring.

FIG. 8 shows a front parallel projection cutout view of a drainingsystem comprising a drainage ring and an O-ring.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

Referring to FIG. 1 , a container 12 comprises a mouth 14. Container 12may, for example, be a bottle or a vacuum bottle. Covering the mouth 14is a cap, such as an elastomeric cap 16, having a sleeve 18 at the upper(distal) end and a widened body 20 at the lower (proximal) end. Sleeve18 of the elastomeric cap 16 may receive a spike 22 in a substantiallyair-tight seal between the exterior surface of spike 22 and a lumen ofsleeve 18. In the present application, the term “proximal” is generallyused to refer to an end or portion of the system that is nearest thecontainer, while the term “distal” refers to an opposite end or portionthat—in use—is near, or within, a patient being treated with the system.

The lower end of spike 22 terminates in a point 24. The upper end ofspike 22 receives a drainage line 26 having a lumen 28 therethrough. Asin the connection between spike 22 and the sleeve 18 of the elastomericcap 16, the connection between spike 22 and drainage line 26 ispreferably substantially air-tight. The spike 22 may also include acircumferential flange 30 to assist in manipulating spike 22 in relationto container 12 in the manner described below. A spike-lumen 19 mayextend through spike.

A frangible seal 32 covers an opening at mouth 14 of the container 12 toseal container interior 13. Frangible seal 32 is preferably constructedof foil, mylar, or other substantially air-tight material, which may beelastomeric, and which may be attached to the edges of the mouth 14 ofthe container 12 to substantially prevent air from leaking into thecontainer interior 13 to spoil the vacuum therein. This attachment canbe accomplished by heat-sealing (as in, for example, direct heat,induction heat or vibration generated heating processes), by gluing oradhesion, or by any other suitable method.

The drainage system 10 may be packaged and shipped in a form thatincludes the container 12 sealed by the frangible seal 32, and with orwithout the other elements. More specifically, the drainage line 26 maybe attached to the rest of the assembly at the time of use, or not.Alternatively, both the spike 22 and drainage line 26 may be attached tothe assembly at the time of use, or not. Or the drainage line 26, spike22 and elastomeric cap 16 may be attached to the assembly at the time ofuse, or not. In may be preferable, but is not necessary, to evacuate thecontainer 12 before shipping.

To use the drainage system 10, it is assembled completely (if notalready assembled completely). The distal end of drainage line 26 (notshown) is attached to a collection device that is placed into a targetfluid space in the patient using a suitable medical technique. Forexample, the distal end of drainage line 26 can be placed in the pleuralspace of the patient to remove excess pleural fluid by means of a needleor catheter.

After engagement with a target fluid space is achieved, spike 22 ispushed toward the container 12 by applying a downward force to theflange 30. This deforms widened body 20 of elastomeric cap 16, whichmaintains the substantially air-tight seal between sleeve 18 and spike22. The spike point 24 meets and pierces frangible seal 32, therebytransferring the vacuum from the container interior 13 into the spacedefined by the elastomeric cap 16 (or, more precisely, thereby drawingnearly all the small quantity of air from the space into the containerinterior to establish a vacuum in that space defined by the cap). Thisvacuum also extends through spike lumen 19 and into drainage line lumen28. The effect is to draw fluid from the distal end of drainage line 26,through the drainage line 26 toward container 12, through the spikelumen 19, and into the container 12.

The rate of fluid withdrawal, and the magnitude of the vacuum applied tothe patient, can be managed by using a clamp on drainage line 26.Opening the clamp slightly will produce a relatively modest vacuum atthe distal end of drainage line 26 and a relatively slow rate of fluidwithdrawal, while opening the clamp will produce a greater vacuum andfaster rate of withdrawal.

It may be important to be able to verify at a glance that the vacuum incontainer interior 13 is intact before using the device. In theembodiment shown in FIG. 1 , this can be accomplished by the appearanceof the elastomeric cap 16. In its normal undistended position, theelastomeric cap will have a given shape that is easily discernible tothe user. As the spike 22 pierces the frangible seal 32 to transfer thecontainer 12 vacuum into the space defined by the elastomeric cap 16,atmospheric pressure on the exterior of the elastomeric cap 16 will tendto partially collapse it. This partial collapse will thus be apparent tothe user, thereby verifying the bottle interior 13 vacuum.

As mentioned above, the vacuum indicator elements also serve to indicatea loss of vacuum over the course of the drainage procedure. Morespecifically, container 12 gradually fills as fluid is drawn out of thepatient, through drainage line 26, and into container 12. This fillingof the bottle of course lessens the vacuum, i.e., it increases thepressure to approach atmospheric. This loss of vacuum and resultingdiminution in fluid flow could be mistaken for a sign that all thedesired fluid has been withdrawn from the patient. The outcome wouldthen be an incomplete procedure. This is prevented by the indicatorelements. If the vacuum becomes insufficient over the course of theprocedure, the indicator elements will so indicate, just as theyindicate if the vacuum is insufficient at the outset of the procedure.

An alternative embodiment of the drainage system 10 is shown in FIG. 2 ,in which the system for verifying the integrity of the vacuum is moreelaborate. The overall configuration is essentially the same as theembodiment of FIG. 1 but with the addition of a collapsible bulb 42.Bulb 42 is in communication with the interior lumen of the spike 22through a tubular fitting 44.

In this embodiment, before spike 22 pierces frangible seal 32 totransfer the vacuum into the spike 22 and drainage line 26, bulb 42 isin its natural undistended state. After spike 22 pierces frangible seal32 to transfer the vacuum into spike 22 and drainage line 26, thedifferential pressure between the vacuum inside bulb 42 and theatmospheric pressure outside bulb 42 collapses or at least partiallycollapses bulb 42. This collapse or partial collapse is readily apparentto the user, thereby confirming the integrity of the vacuum.

Referring to FIG. 3 , elastomeric cap 16 is preferably engaged with(i.e., secured and sealed to) mouth 14 during a drainage procedure. Insome embodiments, as depicted by FIG. 3 , elastomeric cap 16 may besecured to mouth 14 at junction 38 with the use of an adhesive, such assilicone adhesive 40. The adhesive may be, for example, a commonly usedadhesive such as NuSil MED-1037 Silicone Adhesive Sealant. Siliconeadhesive 40 may be applied to an outer surface 34 of mouth 14 and/or toan inner surface 36 of widened body 20, and may operate both to secureelastomeric cap 16 in place with respect to container 12 and to maintainan air-tight seal at junction 38 between outer surface 34 and innersurface 36.

It may be advantageous for elastomeric cap 16 to be removable fromcontainer 12. For example, it may be necessary for a user to flushcontainer 12 to dispose fluid contents from interior 13 shortly after adrainage procedure. In some instances, the disposal of the fluidcontents must occur in a sanitary, controlled manner prior to disposingthe container. Additionally, container 12 may be reusable after it isflushed and cleaned. Because the drainage procedure is often done in apatient home without immediate assistance of a physician or nurse, it isdesirable for elastomeric cap 16 be sufficiently removable (e.g., easilyremovable) such that an at-home patient may perform the removingoperation without trouble. This may limit the device to the use of arelatively low-pressure vacuum. For example, the pressure differentialmay be limited so that removal will require no more than a maximum ofabout 4 pounds of force (about 17 N).

In some embodiments, particularly when container 12 is reusable, it maybe necessary for a user (such as a patient) to attach a new elastomericcap 16 to container 12, potentially without the help of a medicalprofessional. In the embodiment depicted by FIG. 3 , it may be necessaryfor the user to apply an amount of silicon adhesive 40 to outer surface34 and/or inner surface 36 to ensure elastomeric cap 16 properly engageswith mouth 14 and to ensure sufficient sealing at junction 38 to containa vacuum within the device.

As depicted by FIG. 4 , junction 138 may (with reference to thepresently-disclosed embodiments) comprise a silicone or rubber O-ring140 (latex rubber may be acceptable, but generally less preferable thansynthetic rubber, such as—for example—ethylene propylene diene monomer(M-class) rubber). O-ring 140 is preferably made of a material suitablefor undergoing sterility operations and for use in a sterile medicalenvironment. O-Ring 140 may, for example, be a Parker Hannifin, Shore A70 durometer EPDM compound E3609-70 O-ring, but it is not limited tothis model or these particular specifications. The O-ring 140 preferablyprovides an air-tight seal at junction 138 between inner surface 136 ofwidened body 120 and outer surface 34 of mouth 114. The O-ring 140 maybe seated in a groove around the outer surface of mouth 114. A groovemay be additionally or alternatively incorporated into the inner surfaceof widened body 120. It is noted that O-ring 140 could alternatively beplaced in another suitable location for providing a sufficient seal,such as just below (i.e., just proximally) of the elastomeric cap 114.However, a groove is not required. In other embodiments, a bump or beadextending radially outward from surface 34 or mouth 14 may be provided,which may be molded or otherwise formed on container 12, as depicted byFIG. 2 . In this embodiment, an O-ring may be provided directlyproximally or distally of the described bead, which may operate to holdthe O-ring in place.

O-ring 140 may be compressed between an inner surface 136 and outersurface 134. This compression may act to ensure an air-tight seal tofluidly isolate the space defined by the elastomeric cap 116 fromexternal conditions 142. Further, widened body 120 may be slightlytapered at its proximal end such that the compression of O-ring 140increases as widened body 120 moves proximally into engagement withmouth 114. Alternatively or additionally, the distal end of mouth 114may be tapered. In a strongly preferred embodiment, described in furtherdetail below, a silicone O-ring 140 is provided without any adhesive ina manner that still removably secures a fluid-patent (most-preferablyair-tight) seal between the elastomeric cap 116 and the bottle 112,where the cap 116 can be removed from and resealed to the bottle 112, orto a second, similarly—or identically—constructed bottle (not shown)without damaging the O-ring 140.

The shape (e.g., the taper) of widened body 120 may force outer surface134 and inner surface 136 to make contact when elastomeric cap 116 isengaged with mouth 114. The contact may create a point or area offriction that operates to sufficiently secure the elastomeric cap 116 tothe mouth 114. The compressed O-ring 140, when squeezed between surfaces134 and 136, may also provide this securing friction. Any other suitablesecuring means may be used. When in an engaged state, elastomeric cap116 is preferably sufficiently secured to bottle 112 such that it willnot unintentionally fall out of engagement during a drainage procedure.The vacuum in the bottle interior 113 may provide an additional force onelastomeric cap 116 in the proximal direction when frangible seal 132 isbroken. Further, an adhesive, such as a silicone gel, may be appliedeither during the initial assembly or prior to use at junction 138.

While an adhesive can be used even in embodiments with an O-ring, it maybe desirable in some circumstances to forgo using a setting adhesive.For example, it may be useful to remove elastomeric cap 116 prior to (oreven during) normal operation. As described herein, it also may bedesirable to provide a user, such as a patient, with the ability toengage and unengaged elastomeric cap 116 from container 112 without thehelp from a medical professional. The use of an O-ring is advantageousover embodiments requiring the application of an adhesive due to thesimplicity of the engagement operation. The O-ring may eliminate theoften difficult, often unsanitary task of providing a suitable amount ofan adhesive to components before a drainage procedure.

In some cases, it is desirable to inspect the frangible seal 132 priorto using the drainage system 110. The friction between the elastomericcap 116 and bottle 112 may therefore be easily capable of being overcomeby a user, such as a nurse or physician, particularly when the frangibleseal 132 is intact. This may also give a user the ability to removeelastomeric cap 116 from a container 112, which allows the substitutionof one container for another without removing the drainage line 26 (notshown) from communication with a patient. It may further provide theability to select a particular drainage container in a medical facilityimmediately prior to beginning the drainage process, for example toselect a proper size, vacuum level, etc. This gives a user the abilityto select between multiple components to customize or adapt the drainagesystem 110 for optimal performance based on real-time conditions.

It is often necessary or desirable to visually inspect a frangible sealor other components located adjacent to the junction before and duringuse of a drainage system 10. Such inspection can bring to light damagedcomponents, improper operation, insufficient vacuum levels, etc. Inprior designs, particularly those where a elastomeric cap is secured toa bottle with a setting or drying adhesive, it may be necessary toprovide a elastomeric cap 20 made of a transparent material tofacilitate these inspections. In particular, the cap may need to betransparent to facilitate visual inspection of the frangible seal 32 inorder to make certain that it is intact so that the vacuum provided inthe container 12 will provide the desired functionality. A designutilizing an O-ring, as depicted by FIG. 4 , may be advantageous for theability to use a transparent, a translucent, or an opaque elastomericcap 116. To illustrate, an elastomeric cap 116 may be removed from abottle 112, thereby allowing a user to inspect the inner components ofthe elastomeric cap 116 and the components located at the distal end ofcontainer 112. The elastomeric cap 116 may then be re-engaged with acontainer 112 by the user in the manner described above—each withoutdamaging any components. This provides multiple options for inspection,as well as the possibility for ready movement and immediate use of theelastomeric cap (with a second/different bottle) in the event a bottleto which it was connected has a damaged membrane seal or other flaw,where the prior art use of adhesive would make this a moretime-consuming process or even require disposal of the entire assemblyof the elastomeric cap with the bottle.

An embodiment with an O-ring also provides several manufacturing andassembly advantages. For example, an adhesive such as a silicone gel maybe difficult to apply consistently uniformly to the outer surface of amouth of a bottle (and/or the inner surface of the cap) for facilitatingthe securing of an elastomeric cap to the mouth portion, resulting inhigh variability during the assembly process and a large number offaulty or scrap parts. O-rings, on the other hand, are easy to installconsistently without the use of complex machinery and generally come ina pre-manufactured form within small dimensional tolerances and withuniform physical properties. The rate of leakage or failure thereforemay be substantially smaller when using an O-ring. For example, in atest run of bottles assembled according to the presently-describedembodiments, 149 of 150 bottles were successfully assembled with anintact membrane seal of the bottle mouth and with intact seal of theelastomeric cap to the bottle. Use of the presently-described O-ringsystem reduces manufacturing time, complexity, and expense, all of whichprovide advantages over the prior art that would not readily bepredicted by those having skill in the art, and which provide neededefficiencies in the production of medical equipment. This O-ring systemalso provides for the ability to use an elastomeric cap and drainageline with more than one bottle (e.g., if a first bottle's seal isdamaged or its vacuum is otherwise compromised, the bottle can readilybe removed and replaced, or a bottle that is used and filled up may bereplaced, each without having to remove the drainage tube from thepatient).

A drainage system with an O-ring may also cost substantially less thanother embodiments. To illustrate, a single silicone or EPDM O-ring of atype preferably used for embodiments disclosed herein generally costsapproximately 50% of the cost of a suitable amount of a suitablesilicone adhesive needed to secure and permanently seal an elastomericcap to a bottle, while providing a more consistently reliable uniformseal. Using O-rings as an alternative may also reduce the need topurchase and maintain costly manufacturing equipment (e.g., silicone geldispensers), and the highly-consistent assembly associated with theO-ring rather than the silicone adhesive may reduce expenses related tothe number of generated scrap parts. Stated differently, the use of thepresently-described O-ring system provides several advantages—includingcost, device component exchangeability, and device inspectability—ascompared to the prior art silicone adhesive assembly.

Referring to FIGS. 5-8 , embodiments of a drainage system may include aretaining ring 246 with a constricting portion 250. Retaining ring 246is not limited to any particular material, but an exemplary material maybe a random copolymer polypropylene or polyethylene. Retaining ring 246may have one or more weakened areas 252. Weakened area 252 may beembodied as a perforated section, a weakened pinch-joint (as shown),etc. Preferably, weakened area 252 is configured to have a lowercritical strength or breaking strength than the remainder ofconstricting portion 250. A handle or tab 248 may be provided andconfigured to allow a user to provide the necessary force to breakretaining ring 246 at weakened area 252 by pulling on tab 248.

As depicted by FIG. 6 , retaining ring 246 is configured tocircumferentially engage elastomeric cap 216. Retaining ring 246 may betightly wrapped around the outside of widened body 220, therebyproviding a constricting force to retain elastomeric cap 216 inengagement with mouth 214 of container 212. As best shown by FIG. 7 andFIG. 8 , retaining ring 246 is preferably wrapped around elastomeric cap216 adjacent to junction 238 and is radially aligned circumferentiallycoaxially around and just outside of O-ring 240 to provide an inwardconstricting force on elastomeric cap 216 and a reliably consistentuniform seal between the container, O-ring, and cap to patently maintainvacuum. This constriction may provide increased tightness or compressionof O-ring 240, which may improve the performance of the seal at junction238. The constriction provided by retaining ring 246 may make itdifficult (or essentially impossible) for a user to pull elastomeric cap216 out of engagement with container 212 when it is active.

When a user pulls on tab 248 with a force sufficient to break retainingring 246, retaining ring 246 seizes providing the constricting force.Elastomeric cap 216 may then be removed from engagement with container212 relatively easily, and consistently below the desirable maximumthreshold of force for a typical user. Other embodiments of a drainagesystem may alternatively include another type of removable deviceconfigured to provide constriction around elastomeric cap 216, such as asnap-fit belt, a removable tie or wrap, a band clamp, etc.

In some embodiments, retaining ring 246 may be pre-installed at junction238 and providing constriction prior to handing by a user. This mayrequire that elastomeric cap 216 is pre-engaged with container 212 priorto the handling by a user. Alternatively, retaining ring 246 may beprovided with elastomeric cap 216 but separately from container 212.Here, for example, the retaining ring 246 may initially surroundelastomeric cap 216 (or other proximal components, such as a drainageline), but be located proximally of widened body 220. After elastomericcap 216 is moved into engagement with container 212, a user may slideretaining ring 246 distally into position for providing the hereindescribed constriction.

Referring to FIG. 4 , the drainage system 110 may include a stop 160configured to contact a shoulder 162 of container 112. In oneembodiment, which may include a tapered widened body 120 as describedherein, elastomeric cap 116 comprises stop 160 configured to communicatewith shoulder 162 such that it abuts shoulder 162 when a proper level ofengagement with container 112 is achieved. In other words, stop 160 andshoulder 162 may prevent elastomeric cap 116 from sliding too far in theproximal direction when moving into engagement. This can prevent damageto O-ring 140, undesired warping or jamming of components near junction138, etc. The operation of stop 160 may further provide an indication tothe user that a sufficient level of engagement is achieved, therebysignaling the assurance of sufficient securing and sealing at junction138. Although various embodiments of the invention have been described,it will be apparent to those of ordinary skill in the art that many moreembodiments and implementations are possible that are within the scopeof the invention. For instance, steps of a method as displayed in thefigures or reflected in the claims do not require a specific order ofexecution by way they are presented, unless specified. The disclosedsteps are listed as exemplary such that additional or different stepsmay be executed or the steps may be executed in a different order. Thoseof skill in the art will appreciate that embodiments not expresslyillustrated herein may be practiced within the scope of the claims,including that features described herein for different embodiments maybe combined with each other and/or with currently-known orfuture-developed technologies while remaining within the scope of theclaims.

Those of skill in the art will appreciate that embodiments not expresslyillustrated herein may be practiced within the scope of the claims,including that features described herein for different embodiments maybe combined with each other and/or with currently-known orfuture-developed technologies while remaining within the scope of theclaims. Although specific terms are employed herein, they are used in ageneric and descriptive sense only and not for purposes of limitationunless specifically defined by context, usage, or other explicitdesignation. It is therefore intended that the foregoing detaileddescription be regarded as illustrative rather than limiting. And, itshould be understood that the following claims, including allequivalents, are intended to define the spirit and scope of thisinvention. Furthermore, the advantages described above are notnecessarily the only advantages of the invention, and it is notnecessarily expected that all of the described advantages will beachieved with every embodiment. In the event of any inconsistentdisclosure or definition from the present application conflicting withany document incorporated by reference, the disclosure or definitionherein shall be deemed to prevail.

We claim:
 1. A drainage system comprising: a container having aninterior, a mouth, the mouth comprising an outer surface and an opening;a frangible seal covering the opening, the frangible seal having asurface perpendicular to the outer surface of the mouth; a cap securedto the mouth and in fluid communication with a drainage line, the capcomprising a body having an inner surface configured to engage with theouter surface of the mouth and a sleeve that is monolithic with the bodyand that extends away from the mouth; an O-ring located around the mouthand between the outer surface of the mouth and the inner surface of thecap such that the O-ring forms a fluid seal between a space defined bythe cap and environment surrounding the drainage system; and a retainingring formed separately from the cap that is configured to be radiallyaligned with the O-ring and coaxial with the O-ring to provide aconstricting force on the O-ring; wherein the retaining ring comprisinga constricting portion extending around the mouth having a top facingterminal edge, an opposite, bottom facing terminal edge and a facefacing the body of the cap, the face of the constricting portion isentirely contiguous with the body of the cap from the top facingterminal edge to the bottom facing terminal edge.
 2. The drainage systemof claim 1, wherein the retaining ring has a constant inner diameter. 3.The drainage system of claim 1, further comprising a spiked tubepositioned at least partially within the cap and configured to piercethe frangible seal.
 4. The drainage system of claim 3, wherein a vacuumis transferred from the interior of the container to the space definedby the cap, and the interior of the container is in patent fluidcommunication with the space defined by the cap when the frangible sealis pierced.
 5. The drainage system of claim 1, wherein the body of thecap is tapered.
 6. The drainage system of claim 1, wherein the retainingring includes a weakened area with a lower critical strength than anadjacent area such that the retaining ring breaks at the weakened areain response to an input force from a user.
 7. The drainage system ofclaim 1, wherein the interior of the container holds a vacuum.
 8. Thedrainage system of claim 1, wherein a stop extends outwardly from themouth along a shoulder where the container widens to an increasedinternal volume and the retaining ring rests on the stop when theretaining ring is radially aligned with the O-ring and coaxial with theO-ring.
 9. A drainage system, the drainage system comprising: acontainer having a mouth with a first surface surrounding an opening; acap secured to the mouth that comprises a body and a sleeve that ismonolithic with the body and extends away from the mouth, the cap havingan inner surface configured to engage with the first surface of themouth; a drainage line located distally of the cap and in fluidcommunication with a space defined by the cap; and an O-ring locatedbetween the first surface and the inner surface and configured to retaina vacuum within the drainage system; and a retaining ring formedseparately from the cap that is radially aligned with the O-ring andcoaxial with the O-ring to provide a constricting force on the O-ring;wherein the retaining ring comprising a constricting portion extendingaround the mouth having a top facing terminal edge, an opposite, bottomfacing terminal edge and a face facing the body of the cap, the face ofthe constricting portion is entirely contiguous with the body of the capfrom the top facing terminal edge to the bottom facing terminal edge.10. The drainage system of claim 9, the drainage system furthercomprising: a frangible seal covering the opening and maintaining thevacuum within the container while the frangible seal is intact; and atube located at least partially within the cap, the tube having a spike,wherein the spike is configured to pierce the frangible seal.
 11. Thedrainage system of claim 9, wherein the O-ring is configured to providea friction force for securing the cap to the mouth.
 12. The drainagesystem of claim 9, wherein the cap further comprises a tapered portion.13. The drainage system of claim 9, wherein the cap is opaque.
 14. Thedrainage system of claim 9, wherein an interior of the containercontains the vacuum.
 15. The drainage system of claim 9, wherein thedrainage line provides fluid communication with a collection device. 16.The drainage system of claim 9, wherein a stop extends outwardly along ashoulder where the container widens to an increased internal volume andthe retaining ring rests on the stop when the retaining ring is radiallyaligned with the O-ring and coaxial with the O-ring.
 17. A method fordraining a fluid from a patient with a drainage system, the methodcomprising: placing a distal end of a drainage line into contact with atarget fluid, wherein a proximal end of the drainage line contacts andprovides for fluid communication with a cap that includes an inner capsurface, the cap comprising a body and a sleeve that is monolithic withthe body and that extends away from outward from the body in a directionthat is perpendicular to an outer surface of a mouth of a drainagecontainer; moving the body proximally into engagement with the mouth ofthe drainage container such that an O-ring provides a seal between anouter surface of the mouth and the inner cap surface; and sliding aretaining ring proximally over the sleeve and the body of the cap suchthat the retaining ring is radially aligned with the O-ring and coaxialwith the O-ring to provide a constricting force on the O-ring; whereinthe retaining ring comprising a constricting portion extending aroundthe mouth having a top facing terminal edge, an opposite, bottom facingterminal edge and a face facing the body of the cap, the face of theconstricting portion is entirely contiguous with the body of the capfrom the top facing terminal edge to the bottom facing terminal edge.18. The method of claim 17, wherein the cap is opaque.
 19. The method ofclaim 17, further comprising moving the cap distally out of engagementwith the mouth and later moving the cap proximally into sealingengagement around a mouth of a second container.